an 11-year veteran of the secret service, dan bunchino, knows what goes into making it safe. >> we think about what you don't have to, chemical attacks, vehicle-born explosives, a fire. you have to make pennsylvania avenue nearly a quadron of washington, d.c. as secure as the white house. >> reporter: before retiring he was in the elite group assigned to product the president. he walked a few steps from barack and michelle obama in the last inauguration. >> reporter: tell me what it's like when you are walking a few steps away from a presidential limousine or president and first lady and looking at all these buildings. what's going through your mind? >> a little bit of fear. it's like riding a motorcycle. the minute it becomes dangerous is when you're not thinking about it anymore. hands. where is everybody's hands? i can't watch 200,000 hands. but my people are. i'm watching people to make sure they're watching hands and not looking at the parade route. windows, are there any open windows? it's my job to give an umbrella view. every lobby, every window, every floor. it is a massive, mas